Polyps are defined as any growth or mass protruding from a mucous membrane. Polyps can occur wherever there is mucous membrane, namely, in the nose, ears, mouth, lungs, heart, stomach, intestines, urinary bladder, uterus, and cervix. Most polyps are benign growths that eventually stop growing. But some of these polyps keep growing. Genetic mutations can transform them into cancerous tumors. As these cancerous tumors grow larger, they continue growing and begin to burrow deeper and deeper into the tissue supporting the polyp. In the final stages the cancer invades the blood and lymph systems and the malignant cells of the tumor spread to other organs. The problem is particularly severe, yet readily treated, in the colon. Colorectal cancer is the second leading cause of death due to cancer in the United States. If the cancer is detected and treated in its early stages, it can be cured more than 90% of the time. Thus, early detection and removal of colorectal polyps, whether benign, pre-cancerous, or
cancerous, is highly effective in avoiding or treating colorectal cancer.
Polyps may be attached to a mucous membrane by a thin stalk or the polyp may have a broad base. A polyp that is attached by a thin stalk is called a pedunculated polyp and a polyp that is attached by a broad base is called a sessile polyp. Various devices have been proposed for removing polyps, especially pedunculated polyps, from the body. For example, Avellanet, Polypectomy Snare Instrument, U.S. Pat. No. 6,015,415 (Jan. 18, 2000) teaches a polypectomy device using a snare loop connected to a power source to supply cautery current. The snare loop is used to capture the polyp and current is applied to the snare loop which cauterizes the polyp as the snare is closed tightly around the polyp. McKeating, Polypectomy Instrument, U.S. Pat. No. 5,746,747 (May 5, 1998) teaches a polypectomy device using grasping forceps to hold the polyp and a snare wire for cutting the polyp. Electrical current is supplied to the snare wire to cut and cauterize the polyp while the grasping forceps hold onto the body of the polyp. Nakao et al., Surgical Cauterization Snare with Ligating Suture, U.S. Pat. No. 5,906,620 (May 25, 1999) teaches using two snare loops. The first loop cauterizes the polyp while the second loop acts as a suture for ligating the polyp. The second loop is left behind in the colon.